Planographic printing



D. A. NEWMAN PLANOGRAPHIC PRINTING Fled'DeG. 20, 1948 July 26, 195s 2,713,822 Patented July 26, 1955 PLANOGRAPHIC PluN'rlNG Douglas A. Newman, Sea Cliff, N. Y., assigner to Columbia Ribbon and Carbon Manufacturing Company, Inc., Gien Cove, N. Y., a corporation of New York Application December 20, 1948, Serial N o. 66,219

12 Claims. (Cl. lill-149.2)

This invention relates to the art of facsimile printing, and particularly to the production by facsimile printing methods of an inscribed plate or master from which a large number of duplicates may be made, preferably by the planographic printing process.

Facsimile apparatus, for the purposes of this descripl ating a stylus point which correspondingly inscribes the receiving sheet by moving into and out of contact therewith or increasing and decreasing the pressure with which it contacts the same. By means of this form of device, a manifold set, stencil master, or image-forming carbon and planographic plate set may be readily inscribed, so that duplication of the received image offers no serious problems.

The second form of facsimile operation, and the one with which my invention is concerned, uses electrical impulses produced in substantially the same fashion as the rst form. The receiver, however, differs in that an electrically conductive stylus point is caused to make continuous contact with a specially prepared electroconductive sheet mounted on an electro-conductive platen. This sheet has the property of changing its appearance, usually its color, in localities where the passage of current therethrough has occurred. By scanning this sheet in coordination with the scanning operation at the sending device, the local electrically-induced color changes in the sheet may be grouped so as to reproduce exactly the original image scanned by the sending device. This method of operation is known in the art as facsimile printing, and Will be so referred to hereinafter.

While duplicate copies of the image received on the facsimile printer would in many cases be desirable, no method for producing them has been heretofore evolved, and the operation of the device has hence been limited to the production of single copies, duplicates of which could be had only by resorting to the usual expensive and time-consuming methods which involve recopying of the received inscription by photography or otherwise.

It is accordingly an object of my invention to provide a method and equipment for the production of a master, preferably of a planographic nature, solely by means of facsimile printing apparatus, from which master a plurality of duplicate copies may be made directly without the necessity for recopying the received inscription.

In its broader aspects, my invention is concerned with the development of processes and apparatus whereby a planographic printing plate having a base of paper or similar material which is relatively inexpensive and otherwise suitable for routine duplication processes, may

have the oleophilic-hydrophilic balance of its surface locally disrupted to form ink-receptive impressions in response to electrical impulses of the character normally employed in facsimile printing apparatus.

One form of my invention, and that which is at present preferred, makes use of an electro-conductive sheet having a resistance coating on one surface thereof and a fusible transfer coating on the opposite surface, together with a planographic printing plate of any suitable form and preferably having a paper base. The electro-conductive sheet and the planographic plate are so arranged with respect to the recording circuit that the impulses generated therein effect transfer of the coating from the electro-conductive sheet to the surface of the planographic plate to provide water-repellent and inkretaining image thereon.

In connection with this form of the invention certain structural and procedural complications are introduced by the necessity for securing appropriate electrical connection between the electro-conductive sheet and a portion of the circuit, such as the platen on which it is carried, by reason of the interposition of the planographic plate. Consequently it is also an object of my invention to provide a modified planographic plate of paper or the like which is also rendered electro-conductive to an extent sufficient to insure proper operation of the combination without resorting to said undesirable complications, and to provide a method for using the same.

In order to take full advantage of my invention, it must be recognized that a planographic plate is susceptible of being used either directly as a printing member, in which case the image carried thereby must be in reverse, or in a direct-image offset process where the image is transferred irst to an offset blanket and from there to a record sheet. Which process is to be used is normally determined by the availability of equipment to the user, so that it is highly desirable that the plate inscription method and apparatus employed be adaptable to the production of either type of image. While the latter, or direct-image inscription is readily provided by the usual facsimile apparatus, the former is not. Consequently it is an additional object of my invention to provide a facsimile receiver and method for operating the same whereby images of either type may be readily inscribed on a planographic plate.

Since, in practicing the first form of my invention, mentioned above, the electro-conductive sheet and the planographic sheet require placement at about the same time and in fairly accurately related positions, it is a further object of my invention to provide a suitable assembly made up of these elements in order to simplify materially their handling and installation.

Other objects and advantages will hereinafter appear.

In the drawing- Figure l is a plan of an electro-conductive transfer sheet in accordance with the preferred form of my invention.

Fig. 2 is a section on line 2-2 of Fig. 1.

Fig. 3 is a fragmentary diagrammatic view of a portion of an electrical recording device, showing in section the sheets used thereon in the practice of the preferred form of my invention.

Fig. 4 is a View similar to Fig. 3 showing a slightly modified arrangement.

Fig. 5 is a cross section of a modified planographic plate, in accordance with my invention.

Fig. 6 is a view similar to Fig. 3, but illustrating the manner of using the plate of Fig. 5.

Fig. 7 is a diagrammatic plan of a facsimile recording apparatus for use in planographic inscription.

Fig. 8 is a perspective View of an assembly of electroconductive and planographic sheets in accordance with my invention.

Fig. 9 is a section on line 10-10 of Fig. 8.

Fig. 10 is a view similarto Fig. 8 but showing a modified assembly.

My invention is concerned with the inscription of planographic plates by electrical means such as that used in facsimile printing apparatus of the type in general use, and includes as an important element thereof in its preferred form, an electro-conductive transfer sheet 10 shown in Figs. l and 2. The transfer sheet 10 comprises a base web 11 of paper or like material which has been rendered conductive in any appropriate manner. Preferably the pulp from which the paper is made may have mixed therewith a substantial proportion of graphite or carbon black, or other nely divided conductive material such as silver or aluminum, or the finished sheet may be impregnated with any suitable electrolyte carried by an appropriate non-volatile solvent, for example, a solution of sodium nitrate in tri-ethylene glycol.

The conductive web 11 carries thereon a thin coating 12 which has substantial electrical resistance as compared with the web 11, and may consist of any suitable material having the appropriate resistivity as one of its characteristics. For purposes of convenience, the coating 12 is preferably of such a character that its appearance will lchange in response to the passage of an electric current therethrough so that an intelligible inscription will be produced on one surface of sheet 10 simultaneously with its operation as a transfer sheet. One example of a coating suitable for the purpose is a composition comprising lead thiosulphate ground in a binder such as linseed oil. If desired, further light-colored opaque pigments may be added to augment the covering power of the coating and provide a background against which the vinscription can be more clearly distinguished. The coating, after preparation is spread on the conductive base web 11 in a thin, uniform layer having a thickness in the neighborhood of 0.0001 inch, which dries and adheres to the base to form the layer 12. The opposite surface of the web 11 is provided with a thin fusible coating 13 of Wax, or wax-like material which is mixed with suitable plasticizers and hardening agents and, if desired, a pigment. This constitutes the transfer coating and, has the effect of making the portion of any surface to which it becomes attached repellent to water and, at the same time receptive to oleous material. 'As shown in Figs. l and 2, the coating 13 is not coextensive with the base web 11'but is applied so as to leave thereon' an uncoated margin 14 for a purpose hereinafter explained.

In order to practice the method of my invention, an electro-conductive platen 20 (Fig. 3) is provided. This may take the form of the receiving drum of a facsimile printing device. There is first placed on the platen 20 a planographic sheet preferably of paper treated in a known manner such that its upper or outer surface has the necessary hydrophilic-oleophilic balance required for use in planographic printing. The electro-conductive sheet 10, described above, is placed in a position overlying'the sheet 15 with its transfer coating 13 in contact with the planographic surface thereof, and in the form shown the margin 14 of the conductive base web 11 extending beyond the sheet 15 and into contact with the platen 20. v

An electric marking circuit 30 is formed, which includes a suitable source 31 of electric potential and current, and further including platen 20, the conductive web 11, stylus 32, and the portion of the resistance coating 12 directly below the stylus point. When suiiicient voltage is applied by the source 31 across the coating 12 it is found that current passes between the stylus 32 and the conductive web 11. In response thereto a portion of the transfer coating 13 directly below the stylus point is removed from the sheet 10 and deposited on the planographic surface of sheet 15 immediately below.

While the exact nature of the action which takes place is not entirely understood, it is believed that this transfer results from an instantaneous local temperature rise caused by the passage of current through the small overlying area of the electrically resistant coating 12. Furthermore, while the conductive web 11 presents no substantial resistance to the flow of electric current in response to the potentials commonly used, its conductivity is still apparently sufficiently reduced to cause the heat generated by the current passage to be confined to the immediate locality with the result that the fusible coating 13 is softened and transferred in a restricted area directly below the stylus point. In any event, the operation of the device using the materials described effects transfer of a portion of coating 13 to the surface of sheet 15 in an area which conforms very closely to that covered by the point of the energized stylus.

In case the preferred materials described above are used in compounding the coating 12, a visible mark on the surface of sheet 10 will likewise appear, giving a continuous visible indication of the inscription which is being received by the planographic plate.

The transfer of the material from coating 13 to the surface of sheet 15 may or may not leave a readily visible mark thereon, depending on whether a pigment is included in the composition of coating 13. In either case the surface portions of sheet 15 which carry the material transferred from the coating 13 have been made water-repellent and ink-receptive. The sheet 15 is therefore in condition to be used as a master from which copies may be made by the usual planographic process.

The arrangement shown in Figure 4 is similar to that of Fig. 3, the only change being that, instead of relying upon the flexibility of the marginal portion of sheet 10 to secure an electric contact with the platen 20, an additional element in the form of a thin band or ring 21.01" conductive material is attached to the platen 20 at an appropriate location preferably near one end thereof. Sheets 10 and 15 are assembled on the platen in a relationship clearly shown in Fig. 4 and with the overhanging marginal portion 14 of the conductive web 1.1 in contact with the band 21.

Fig. 5 illustrates a modified planographic plate which may be used to advantage in carrying out my invention.

y This form of plate is designated by the character 15a and comprises a sheet of paper or like material 16a having the high wet-strength and low wet-extensibility which makes it suitable for use as a planographic plate. In addition, the paper sheet 16a is formed in such a way that it has substantial electrical conductivity, for example in a manner similar to the preparation of the base web 11 of the transfer sheet 10 described above. One surface of the sheet 16a is treated by the application thereto of a` coating 17a. This coating has the property of giving to the surface of the sheet 16a the appropriate hydrophilic-oleophilic balance suitable for planographic work and may consist of any one of several compositions known to be suitable forthis purpose. The preferred coating used in this connection consists essentially of a water insoluble compound of carboxymethyl cellulose. Also included in the composition of the coating 17a is any conductivity-producing element, for example finely divided silver, aluminum, titanium dioxide or zinc oxide which will not affect the balance of the coating from the standpoint of its planographic printing operation, but which lends substantial conductivity thereto so that the electrical resistance through any portion of the plate 15a is low, at least in comparison with the resistancev of the transfer coating 13 of the sheet 10, or of the sheet 10a hereinafter described.

When a plate 15a in accordance with'the above description is to be used, the simplied recording arrangement of Fig. 6 may be employed. In this case the electro-conductive transfer sheet 10a may have its transfer coating 1.3 coextensive therewith, the exposed marginal portion of the conductive web 11 being unnecsary. The sheets isa and 10a are placed on the platen 20 in the relationship shown in Fig. 6 and the operation proceeds in the manner described above for Fig. 3. In this case, however, the source of electrical energy 33 in the marking circuit 30a is represented as being a generator of alternating high-frequency current to illustrate the proposition that the currents used in facsimile apparatus of this type are normally of this character. It will be noted that in the arrangement shown in Fig. 6 a direct flow of electric current through the circuit is substantially precluded due to the insulating layer of transfer material 13. However, the fact that the sheet 15a is made conductive and that the insulating layer 13 is extremely thin provides an arrangement which, in cooperation with the conductive web 11, acts as a condenser of substantial capacity whereby displacement current at the frequencies ordinarily employed for facsimile transmission is passed. In this manner the necessity for the overlapping contact margin i4 on the conductive web 11 is avoided and the elements 10a and 15a may be positioned on the platen without giving undue attention to the accuracy of their location.

When a facsimile printing apparatus is used in the normal fashion to produce planographic plates by any of the methods described above, the resulting image will normally be direct reading. This being the case, the plates inscribed are usable only in printing apparatus of the offset type. in certain cases, however, where the offset process is impractical for any reason, usually due to the unavailability of the proper equipment, it is dcsirable to use my invention in such a way that the inscribed plate may take part in a direct printing process. In order to accomplish this result, I have developed as a part of my invention a modified facsimile printing a paratus and a method for using the same. This is illustrated in Fig. 7 wherein is shown a facsimile recording system including a sending device 5d and a receiving device 6i). The sending device consists of a rotary platen 51 and stylus 52 both of which are driven by a motor 53 and whose movements are coordinated in such a way that the stylus traverses the platen in a helical path in the well-known manner. As is usual in devices of this character the engagement of the stylus point 52 with a non-conducting portion of the sending blank 54 initiates l-;

an electrical impulse in the ending circuit which impulse is amplified by the sending amplifier, 55 passes over the usual communications lines, 55 is again amplified by the receiving amplifier 65 and proceeds to the recording circuit of the receiving device 60. This device consists of a rotary receiving platen 61 and a receiving stylus 62. driven by a motor 63. The motions of the platen and the stylus are so coordinated that the stylus 62 will traverse a helical path on the receiving platen 61 which corresponds directly to that traversed by the sending stylus S2 on the sending platen 51 by virtue of the usual synchronous interconnection of the motors. In addition I provide the reversing mechanism 66, diagrammatically indicated in Fig. 7, by means of which the direction of rotation of the platen with respect to the direction of movement of the stylus may be reversed. Any suitable mechanical or electrical reversing mechanism which can be inserted in the interconnection between the stylus drive and platen drive may be used, the particular arrangement of Fig. 7 being used purely as an example.

When the inscription of a receiving blank 64 which comprises a planographic plate such as 15, 15:1, or 15b is being carried out by a receiving apparatus 60, the same may be accomplished in a direct reading form by placing the reversing transmission 66 in the direct position as shown in fuil lines in Fig. 7. Likewise when a reverse reading plate for direct printing is desired the transmission 66 may be placed in reverse position as indicated by the dotted line position R.

Je C

In the practice of my invention according to Figs. 3 to 6 and as described above, it is seen that two sheets must be placed on an electro-conductive platen at substantially the same time and, particularly in the form of Figs. 3 and 4, located with some degree of accuracy. In order to prevent such an operation from being burdensome and ineicient, I provide an assembly of sheets wherein the relative position is accurately xed so that the operator is merely required to place the same on the platen in a manner similar to that which would be used in the case of a single record sheet. Thus in Figs. 8 and 9 there is shown an assembly i0 consisting of an electroconductive sheet 1t) having the overhanging conductive undermargin i4 and the transfer coating 13. The sheet it) is registered with a planographic plate or sheet 1S in such a way that the planographic surface is directly opposite and coextensive with the transfer coating i3 so that the adjacent edges on three sides are contiguous, and on the other are offset to leave the marginal portion i4 uncovered. The sheets may be secured together along any of the contiguous edges by suitable connecting means. Preferably this will consist of an extremely thin tape 41, embracing the margins of the sheet adjacent the contiguous edges which are opposite the offset edges, and adhered to the outer surfaces and edges of the sheets. While my invention in its broader aspect, includes a construction wherein a single sheet is treated in one part thereof `so as to form a planographic plate and in another part to form an electro-conductive transfer sheet, and then folded upon itself to form an assembly, the treatments required are of such divergent character, it is presently preferred to treat the sheets individually and attach them in a manner similar to that described above.

it is frequently desirable to have certain standard headings or other inscription provided on a planographic plate in addition to the matter which is to be recorded thereon. Consequently, in such cases, the plate l5 is provided on its planographic surface with an ink-receptive imprint 43 of such standard matter, which imprint will operate to produce an image on the copies made therefrom together with and in the desired relationship to the image of the recorded matter.

As a protective measure to prevent accidental transfer of portions of the coating 13 to the plate i5 before the desired controlled transfer takes place, a slip sheet 42 of suitable material, preferably tissue paper, may be inserted between the sheets Ato be removed just prior to use. In this fashion, transfer due to rough handlinfy or to excessive pressure in storage stacks, and which might result in serious defacement of the printed copies, is avoided.

The assembly 46a, shown in Fig. l0, is designed to serve the needs of the operation in accordance with the practice as outlined in connection with Fig. 6 and is similar to the assembly of Fig. 8, except that the electro-conductive planographic sheet 15a is substituted for the sheet i5, the transfer sheet Mia is substituted for the sheet 1i) and the sheets are of substantially equal size, the conductive margin on the transfer sheet beinry unnecessary in this form.

After inscription of either the set it@ or the set iia in the described manner, the same will be removed from the platen, the parts thereof separated, and the plate 15 or 15a is then used as the printing element in a planographic process in accordance with well-known procedures.

Variations and modications may be made within the scope of this invention and portions or" the improvements may be used without others.

I claim:

l. A transfer sheet for the production of inscribed planographic plates using electric recording apparatus, comprising a sheet of electro-conductive material having on one surface a coating of a relatively non-conductive fusible transfer material, and having on the opposite surface an electrically conductive resistance layer, a portion of said one surface being tree of said coating whereby the sheet may make contact with an electric recording platen. v v

2. A transfer sheet for the production of inscribed planographic plates using electric recording apparatus, comprising a sheet of electro-conductive material having on one surface a coating of a relatively non-conductive fusible transfer material, and having on the opposite surface an electrically conductive resistance layer; a marginal portion of said one surface being free of said coating whereby the sheet may make Contact with an electric recording platen.

3. A transfer sheet for the production of inscribed planographic plates using electric recording apparatus, comprising a sheet of electro-conductive material having on one surface a coating of a relatively non-conductive fusible transfer material consisting primarily of wax, and having on the opposite surface an electrically conductive resistance layer of a character such that it can be activated by the passage of electric current therethrough to change appearance in a manner to eiect a visible inscription on the sheet; a portion of said one surface being free of said coating whereby the sheet may make contact with an electric recording platen.

4. A transfer sheet for the production of inscribed planographic plates using electric recording apparatus comprising a sheet carrying an electrical resistance layer on one surface and a fusible oleophilic transfer material on the opposite surface of the sheet, said electrical resistance layer having such value as to generate localized areas of heat over said layer of fusible material to fuse and release the same in image form in response to stylusdirected, image-delineating electric currents applied thereto.

5. A transfer sheet for the production of inscribed planographic plates using electric recording apparatus comprising an electro-conductive sheet carrying an electrical resistance layer on one surface and a fusible oleophilic transfer material on the opposite surface of the sheet, said electrical resistance layer having such value as to generate localized areas of heat over said layer of fusible material to fuse and release the same in image form in response to stylus-directed image-delineating electric currents applied thereto.

6. A unit for making a planographic printing plate by the use of electric recording means employing an electrically-conductive, image-delineating scanning stylus riding over a platen in accordance with an original comprising a planographic printing plate and an electroconductive transfer sheet adapted to be electrically connected with the platen having a substantial electrical resistance and a coating of image-forming fusible oleophilic material on one surface superimposed over said plate with the fusible material in face-to-face contact with the printing surface of said plate, said oleophilic material being so fusible as to fuse in localized imaged areas defined by the path of the stylus under the heat generated by the passage of the stylus electric current through the transfer sheet and simultaneously adhere in image form on the printing surface of said plate.

7. A unit for making a planographic printing plate by the use of electric recording means employing an electrically-conductive, image-delineating scanning stylus riding over a platen in accordance With an original cornprising a planographic printing plate and a transfer sheet adapted to be electrically connected with the platen including an electroconductive base web having a layer of material with a substantial electrical resistance on one surface and a coating of image-forming fusible oleophilic material on the other surface superimposed over said plate with the fusible material in face-to-face Contact with the printing surface of said plate, said oleophilic material being so fusible as to fuse in localized imaged areas defined by the path of the stylus under the heat generated by the passage of the stylus electric current through the resistance material and simultaneously adhere in image form on the printing surface of said plate.

8. The method of forming a facsimile planographic image on a planographic plate through the medium of a superposed transfer sheet having a substantial electrical resistance and provided on one surface With a layer of image-forming fusible oleophilic material which includes the steps of scanning over the transfer sheet with a stylusdirected, image-delineating current in accordance with an original, generating heat in localized areas scanned by said stylus by the passage of current through the transfer sheet and fusing image-forming portions of the layer of fusible transfer material on the transfer sheet and simultaneously adhering said fused imaged portions to the underlying planographic printing surface of the planographic printing plate to produce a printing image thereon.

9. The method of forming a facsimile planographic image on a planographic plate through the medium of a superposed electroconductive transfer sheet having a layer of material with a substantial electrical resistance on one surface and a layer of image-forming fusible material on the other surface which includes the steps of scanning over the resistance layer on the transfer sheet with a stylus-directed, image-delineating current in accordance with an original, generating heat in localized areas scanned by said stylus by the passage of current through the resistance layer of the transfer sheet, fusing image-forming portions of the layer of fusible transfer material on the transfer sheet and simultaneously adhering said fused imaged portions to the underlying planographic printing surface of the planographic printing plate to produce a printing image thereon.

l0. A unit for making a planographic printing plate by the use of electric recording means employing an electrically conductive, image-delineating scanning stylus riding over a platen in accordance with an original comprising a planographic printing plate including a base member primarily of cellulosic material impregnated with an electrically conductive substance and a hydrophilicoleophilic coating forming the printing surface having an electrically conductive material dispersed therein to render said resulting plate electroconductive; and an electroconductive transfer sheet having a substantial electrical resistance and a coating of fusible olephilic material on one surface superimposed over said plate with the fusible material in face-to-face contact with the printing surface of said plate, said oleophilic material being so fusible as to fuse in localized imaged areas dened by the path of the stylus under the heat generated by the passage of the stylus electric current through the transfer sheet and simultaneously adhere in image form on the printing surface of said plate.

ll. A unit for making a planographic printing plate by the use of electric recording means employing an electrically conductive, image-delineating scanning stylus riding over a platen in accordance `Vith an original comprising an electroconductive planographic printing plate having dispersed in a hydrophilic-oleophilic coating forming the printing surface an electrically conductive material to render said coating electroconductive; and an electroconductive transfer sheet having a substantial electrical resistance and a coating of fusible olephilic material on one surface superimposed over said plate with the fusible material in face-to-face contact with the printing surface of said plate, said oleophilic material being so fusible as to fuse in localized imaged areas dened by the path of the stylus under the heat generated by the passage of an induced stylus electric current through the transfer sheet and simultaneously adhere in image form on the printing surface of said plate.

l2. The method of forming a facsimile planographic image on a planographic plate through the medium of a superposed transfer sheet having a substantial electrical resistance and provided on one surface With a layer of fusible oleophilic material which includes the steps of scanning over the transfer sheet with an induced stylusdirected, image-delineating current in accordance with an 9 10 original, generating heat in 1ocalized areas scanned by said 2,279,242 Orien Apr. 7, 1942 stylus by the passage of current through the transfer sheet 2,294,146 Wise Aug. 25, 1942 and melting the image-forming portions of t'ne layer of 2,311,047 Hagelin Feb. 16, 1943 fusible transfer material on the transfer sheet and simul- 2,317,789 Marriot Apr. 27, 1943 taneously adhering said melted portions to the underlying 5 2,322,367 Kjeilstrand June 22, 1943 planographic printing surface of the planographic printing 2,322,903 Wiikof June 29, 1943 plate to produce a printing image thereon. 2,329,332 Bull Sept. 14, 1943 2,346,670 Engler Apr. 18, 1944 References Cited in the le of this patent 2,396,833 DHumy Man 19, 1946 UNITED STATES PATENTS 10 2,397,616 Mullen Apr. 2, 1946 39 7 2 1,656,338 Ranger Eau. 17, 1928 AS 179 Dfllton et al Apr 3 1946 ,-f 3,484 oung Nov. 9, 1948 1,800,560 Neidlch Apr. 14, 1931 n 500 617 M 2, l i elgs Mar. 14, 1950 1,802,379 Hlggmson APT- 28 1931 2,534,553 'Wol-then Dea 19, 1950 12819264 Rangel Aug' 18 191 1; 2,542,784 van Busen Feb. 20, 1951 1,901,921 Means Mar. 2l, 1953 7 616 961 G 1 2, r real` Nov. 4, 1952 Wlidhaber NOV- 14, f; Eilfon Dec 2,142,250 Neidich Jan. 3, 1939 2,181,533 Kline Nov. 28, 1939 FOREIGN PATENTS 2,268,703 Rubinstein July 23, 194() 20 550,575 Germany of 1932 2,216,594 Marchev Oct. 1, 1940 

